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Abstract We construct localized beams in a non-Hermitian Glauber Fock (NGF) lattice of coupled waveguides and show that they can propagate over a long distance withalmost no diffraction. We specifically obtain the diffraction-free beams in a finite NGF lattice at the exceptional point (EP) by using the exact eigenstates of the semi-infinite unidirectional NGF lattice. We provide a numerical approach to finding other lattices that are capable of supporting non-diffracting beams at EPs.
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Non-diffracting states at exceptional points
We propose to use exceptional points (EPs) to construct diffraction-free beam propagation and localized power oscillation in lattices. We specifically consider two systems to utilize EPs for diffraction-free beam propagation, one in synthetic gauge lattices and the other in unidirectionally coupled resonators where each resonator individually is capable of creating orbital angular momentum (OAM) beams. In the second system, we introduce the concept of robust and tunable OAM beam propagation in discrete lattices. We show that one can create robust OAM beams in an arbitrary number of sites of a photonic lattice. Furthermore, we report power oscillation at the EP of a non-Hermitian lattice. Our research widens the study and application of EPs in different photonic systems including OAM beams and their associated dynamics in discrete lattices.
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- Award ID(s):
- 2012172
- PAR ID:
- 10212750
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 46
- Issue:
- 4
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 765
- Size(s):
- Article No. 765
- Sponsoring Org:
- National Science Foundation
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